An apparatus and method for cleaning and drying compressed air

Abstract

An apparatus and method for cleaning and drying compressed air. The apparatus includes a bracket, a pre-filter, a control box, an adsorption twin-tower dryer, and a post-filter. The adsorption twin-tower dryer includes an air inlet end cover, an aluminum alloy cylinder body, an air outlet end cover, and a check valve assembly. Inside the aluminum alloy cylinder body, there are a first diffusion structure, a first support frame, an adsorption material encapsulation cylinder, a protection device, a second support frame, and a second diffusion structure, forming an adsorption tower body or a backflush regeneration tower body. The check valve assembly is installed inside the air outlet end cover, and a flow channel for backflush regeneration gas is provided on the check valve assembly. The present invention also provides a method for cleaning and drying compressed air. By using the present invention, the inherent defect of generating dust during the use of the existing drying bead dryer can be solved, and it will not become a secondary pollution source for air source treatment. The backflush regeneration efficiency can be improved, and the output pressure of the dryer can always be kept stable.

Description

Technical Field

[0001] The present invention relates to a device and method for cleaning and drying compressed air. Background Art

[0002] In applications in the microelectronics industry, pharmaceutical industry, industrial automation industry, rail transit industry, food and beverage industry, etc., extremely high requirements are put forward for the cleanliness and drying level of compressed air or certain industrial gases, in order to improve production efficiency and reduce the failure rate and maintenance cost of downstream equipment.

[0003] Conventional adsorption dryers can treat impurities such as water mist, particles and oil contained in compressed air or certain industrial gases, and provide clean and dry gas for downstream equipment. However, there are inherent defects such as pulverization and degradation of the adsorption medium and rapid attenuation of the dryer performance during application / use. For example, in the existing double-tower compressed air dryer, the adsorption tower is filled with a certain number of drying beads (made of a mixture of adsorption media such as aluminosilicate, activated alumina, silica gel and clay) in a container. The water-containing compressed air enters from one end of the container. When passing through the drying beads, the moisture in the compressed air is adsorbed by the adsorbent, and thus dry compressed air is obtained. The dry compressed air is output from the other end of the container. After a certain period of time, the states of the two adsorption towers of the dryer are reversed. The originally dry adsorption tower becomes backflush regeneration, while the previously backflush regenerated tower becomes the adsorption tower, and so on, to ensure that the compressed air dryer can be in a continuous working state. However, since the drying beads are mostly prepared in spherical or a certain specific shape from materials such as aluminosilicate or alumina and a certain proportion of clay, when high-pressure and high-speed compressed air flows through the tower filled with drying beads, under the blowing of the high-pressure and high-speed compressed air, the surfaces of the drying beads rub against each other, generating some extremely fine powders. These powders flow out of the adsorption tower with the compressed air and enter the downstream equipment, making the drying bead dryer a secondary pollution source in compressed air treatment. Therefore, at least two stages of high-precision filters must be configured at the rear end of the drying bead dryer to filter impurities such as dust generated by the powder of the drying beads themselves. At the same time, due to the characteristic that the drying beads containing clay will degrade when soaked in water, under the action of water-containing compressed air, the pulverization of the drying beads will be greatly accelerated, resulting in rapid attenuation of the dryer performance. In addition, existing dryers usually need to set up an independent backflush regeneration gas channel and a throttling device in the outlet end cover. Therefore, the backflush regeneration gas cannot be ejected from the central position, resulting in poor backflush regeneration efficiency of the dryer. Existing dryers usually use backflush regeneration gas for pressure maintenance, and open or close the intake channel during the switching of the two towers. Therefore, the output pressure of the dryer is prone to fluctuations and cannot achieve continuous and stable output pressure. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device and method for cleaning and drying compressed air that can solve the inherent defect of dust generation in the use of existing drying bead dryers, will not become a secondary pollution source for air source treatment, can improve the backflush regeneration efficiency, and can keep the output pressure of the dryer stable all the time.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0006] A device for cleaning and drying compressed air, comprising a bracket, a pre-filter, a control box, and an adsorption twin-tower dryer. The pre-filter and the control box are installed on the front side of the bracket, and the adsorption twin-tower dryer is installed on the rear side of the bracket. The pre-filter and the adsorption twin-tower dryer are connected by a pipeline.

[0007] The adsorption twin-tower dryer includes an air inlet end cover, an aluminum alloy cylinder body, an air outlet end cover, and a one-way valve assembly. The air inlet end cover is installed on the bracket. There are two aluminum alloy cylinder bodies, which are respectively installed between the air inlet end cover and the air outlet end cover. Inside each aluminum alloy cylinder body, there is a first diffusion structure, a first support frame, an adsorption material encapsulation cylinder, a protection device, a second support frame, and a second diffusion structure. The adsorption material encapsulation cylinder is composed of an encapsulation end cover, an aluminum alloy cylinder body, and sheet-shaped adsorption materials. The sheet-shaped adsorption materials are in a long-strip multi-layer winding structure inside the aluminum alloy cylinder body, and the gap between each layer is a gas flow channel. The first diffusion structure and the first support frame are installed on the air inlet end cover. The adsorption material encapsulation cylinder is installed on the first support frame. The protection device is installed on the adsorption material encapsulation cylinder. The second support frame is installed between the protection device and the air outlet end cover. The second diffusion structure is installed on the air outlet end cover to form an adsorption tower body or a backflush regeneration tower body. There are two one-way valve assemblies, which are respectively installed inside the air outlet end cover. Each tower body is controlled by an independent one-way valve assembly. The one-way valve assembly is provided with a flow channel for backflush regeneration gas.

[0008] The air inlet end cover is provided with an air inlet channel, an exhaust channel, and an air outlet channel. On the outer side of the air inlet end cover, there are two control solenoid valves, one corresponding to each tower body. All control solenoid valves are connected to the control box to switch the working state.

[0009] Further, the aluminum alloy cylinder body is connected to the air inlet end cover and the air outlet end cover by bolts through the threaded holes on both sides, and an O-ring is arranged between the aluminum alloy cylinder body and the air inlet end cover and the air outlet end cover for sealing.

[0010] Further, one side of the first diffusion structure is a precision machined concave surface body. Four counterbores are arranged on the outer circumference of the first diffusion structure for fitting the heads of the four bolts for locking the first diffusion structure into the first diffusion structure. The second diffusion structure is the same as the first diffusion structure.

[0011] Furthermore, both the first support frame and the second support frame are cylindrical structures.

[0012] Furthermore, the protection device is a flat structure with a spoke shape. Four spokes are arranged between the solid hub and the rim. The solid hub presses against the center of the adsorption material encapsulation cylinder, and the rim is located between the adsorption material encapsulation cylinder and the second support frame.

[0013] Furthermore, the one-way valve assembly includes a one-way valve cover plate, a guide sleeve, a one-way valve cover plate sealing ring, a one-way valve spring, and a one-way valve plate. The guide sleeve is installed on the one-way valve cover plate. The one-way valve spring is sleeved on the outer side of the upper part of the one-way valve plate, and the upper end of the one-way valve plate extends into the guide sleeve. The one-way valve cover plate is installed on the air outlet end cover, and the one-way valve cover plate sealing ring is installed between the one-way valve cover plate and the air outlet end cover. A vulcanized rubber is provided on the lower end surface of the one-way valve plate, and a communication hole is provided on the one-way valve plate as the flow path for the backflush regeneration gas.

[0014] Furthermore, the control solenoid valve is a normally open function solenoid valve with two positions and three passages and spring return.

[0015] Furthermore, a muffler is installed at the outlet of the exhaust passage.

[0016] Furthermore, a post-filter is also provided, and the post-filter is installed at the air outlet of the adsorption type twin-tower dryer.

[0017] The method for cleaning and drying compressed air using the said device is as follows:

[0018] The compressed air generated by the compressor enters the pre-filter through the air inlet for pretreatment. The compressed air treated by the pre-filter enters the adsorption type twin-tower dryer. The adsorption type twin-tower dryer removes the gaseous water contained in the compressed air and discharges it from the air outlet to provide dry compressed air for the downstream equipment, and switches the states of the twin towers according to the timing set in the control box;

[0019] Specifically, by controlling the action of the control solenoid valves of the adsorption tower body and the backflush regeneration tower body through the control box, the state of the dryer tower body is determined. That is, for the tower body in the adsorption state, its air inlet passage is communicated with the air outlet passage, so that the compressed air enters the tower body for adsorption drying, while the exhaust passage is not communicated with the air outlet passage, and the compressed air can only flow towards the air outlet end cover side; at the same time, for the tower body in the backflush regeneration state, its air inlet passage is not communicated with the air outlet passage, so that the compressed air cannot enter the tower body, while the exhaust passage is communicated with the air outlet passage, so that the backflush regeneration gas can flow out of the tower body and enter the exhaust passage to be discharged to the atmosphere;

[0020] Inside the adsorption tower body, compressed air flows out from the air inlet of the inlet end cover. Under the action of the first diffusion structure installed on the inner side of the inlet end cover, it blows evenly around the aluminum alloy cylinder body. At the same time, the first support frame arranged between the inner side of the inlet end cover and the adsorption material encapsulation cylinder constructs a sufficient space to further reduce the flow rate of the compressed air, ensuring that the compressed air passes through the adsorption material encapsulation cylinder evenly and at a low speed, and ensuring that the adsorption material fully adsorbs the moisture in the compressed air. A protection device is arranged at the rear end of the adsorption material encapsulation cylinder and is fixed above the adsorption material encapsulation cylinder by the second support frame above the protection device. The protection device fits with the boss at the center of the adsorption material encapsulation cylinder to enhance the support strength of the adsorption material encapsulation cylinder and ensure that the adsorption material encapsulation cylinder works stably and safely under high pressure; the compressed air after drying treatment passes through the one-way valve assembly and then is discharged from the flow channel in the outlet end cover of the adsorption type double tower dryer;

[0021] Inside the backflush regeneration tower body, the regeneration gas flowing out from the adsorption tower body blows out from the hole in the center of the one-way valve assembly. Under the action of the second diffusion structure on the inner side of the outlet end cover, the regeneration gas blows evenly around the aluminum alloy cylinder body. At the same time, the second support frame arranged between the inner side of the outlet end cover and the adsorption material encapsulation cylinder constructs a sufficient space to further reduce the flow rate and pressure of the regeneration gas, ensuring that the regeneration gas completely purges the water vapor precipitated in the adsorption material, improving the regeneration efficiency and reducing the consumption of the backflush regeneration gas;

[0022] When the state of the double tower is about to switch, under the control of the preset program in the control box, the control solenoid valve of the tower body in the backflush regeneration state acts, making its air inlet channel and air outlet channel become connected, and compressed air can enter the tower body, while the exhaust channel and the air outlet channel become disconnected, and the compressed air can only flow towards the outlet end cover side. At this time, the adsorption material encapsulation cylinder in the tower body starts to adsorb the moisture in the compressed air, that is, it has been converted into an adsorption tower, and the pressure in the tower body rises rapidly in a short time. When the check valve plate in the one-way valve assembly of the original backflush regeneration tower body is fully opened, the pressure in the original backflush regeneration tower body is the same as that in the adsorption tower body. This process is called the pressure holding stage of the backflush regeneration tower; under the control of the preset program in the control box, the control solenoid valve of the tower body in the adsorption state acts, its air inlet channel and air outlet channel become disconnected, so that compressed air can no longer enter the tower body, while the exhaust channel and the air outlet channel 2 become connected, so that the gas in the adsorption tower body quickly flows out of the tower body and enters the exhaust channel and is discharged to the atmosphere. During this process, the pressure inside the adsorption tower body drops rapidly, resulting in the rapid closing of the check valve plate in its one-way valve assembly, and the backflush regeneration gas reversely enters the tower body from the communication hole, making its state converted into the backflush regeneration state; thus the state of the double tower has switched. Under the control of the preset program in the control box, the states of the double tower are cyclically switched, so that the adsorption type double tower dryer can work continuously.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. During the operation of the dryer, there is no dust product, solving the inherent defect of dust generation in the use of the drying bead dryer in the prior art, and it will not become a secondary pollution source for air source treatment; the adsorption material of the dryer can be resistant to water saturation and will not degrade after being soaked in water for a long time, has extremely strong oil resistance and can restore the performance of the adsorption material through cleaning; the dryer can operate stably under harsh environments and working conditions. With guaranteed maintenance, the service life of the adsorption material encapsulation cylinder reaches more than 30,000 operating hours; the performance of the dryer is not affected by the installation method and can be installed horizontally or vertically; the performance of the dryer is not affected by external factors such as vibration or impact;

[0025] 2. With the assistance of fluid calculation and finite element simulation, a diffusion structure is designed, and the support space on both sides of the adsorption material encapsulation cylinder is determined through verification of a large amount of test data, ensuring that under the combined action of the diffusion structure and the support space, the compressed air passes through the adsorption material encapsulation cylinder evenly and at a low speed, enabling the adsorption material to fully adsorb the moisture in the compressed air. During backflush regeneration, the regeneration gas purges the adsorption material evenly, improving the regeneration efficiency and reducing the consumption of backflush regeneration gas;

[0026] 3. A small hole is drilled in the one-way valve plate to be used as the flow channel for the regeneration gas during the backflush regeneration of the drying tower, ensuring that the backflush regeneration gas blows out from the center and evenly blows towards the periphery of the dryer tower body under the action of the diffusion structure. At the same time, there is no need to separately arrange the regeneration gas flow channel and flow control device on the outlet end cover, simplifying the flow channel design of the end cover and reducing components to improve the reliability of the dryer;

[0027] 4. Ensure that the output pressure of the dryer is not affected during the switching of the two towers. Under the control of the preset program in the control box, when the backflush regeneration tower finishes regeneration and enters the pressure holding stage, by opening the intake passage of the control solenoid valve of the backflush regeneration tower, the upstream compressed air enters the backflush regeneration tower, causing the pressure of the backflush regeneration tower to rapidly rise to the same as the pressure in the adsorption tower in a short time, that is, at the end of the pressure holding stage, the one-way valves of both the backflush regeneration tower and the adsorption tower will be fully opened. During the switching of the two towers, by closing the intake passage of the control solenoid valve of the original drying tower and opening the exhaust passage of the regeneration gas, the original drying tower becomes the one for backflush regeneration, realizing the switching of the two-tower state. During this process, since the pressures of the backflush regeneration tower and the drying tower are the same, the output pressure of the dryer remains unchanged during the switching process, achieving a stable output pressure of the dryer at all times. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the front view of the embodiment of the present invention;

[0029] Figure 2 isFigure 1 Rear view sectional view of the illustrated embodiment;

[0030] Figure 3 is Figure 1 Schematic structural diagram of the check valve assembly of the illustrated embodiment;

[0031] Figure 4 is Figure 1 Schematic diagram of the air intake structure of the illustrated embodiment;

[0032] Figure 5 Schematic three - dimensional structure diagram of the embodiment of the present invention;

[0033] In the figure: 100. Post - filter; 200. Adsorption twin - tower dryer; 300. Control box; 4. Pre - filter; 500. Bracket; 201. Air intake end cover, 201 - 1. Control solenoid valve, 201 - 2. Air intake channel, 201 - 3. Exhaust channel, 201 - 4. Air outlet channel, 201 - 5. Muffler; 202. First diffusion structure; 203. First support frame; 204. Adsorbent material encapsulation cylinder; 205. Protection device; 206. Second support frame; 207. Air outlet end cover; 208. Check valve assembly, 208 - 1. Check valve cover plate, 208 - 2. Guide sleeve, 208 - 3. Check valve cover plate sealing ring, 208 - 4. Check valve spring, 208 - 5. Check valve plate, 208 - 6. Communication hole; 209. O - ring; 210. Aluminum alloy cylinder; 211. Second diffusion structure; a. Air inlet, b. Air outlet. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] Refer to Figures 1 - 5 , a device for cleaning and drying compressed air, comprising a bracket 500, a pre - filter 400, a control box 300, an adsorption twin - tower dryer 200 and a post - filter 100. The pre - filter 400 and the control box 300 are installed on the front side of the bracket 500, the adsorption twin - tower dryer 200 is installed on the rear side of the bracket 500. The pre - filter 400 and the adsorption twin - tower dryer are connected by a stainless - steel hard pipe. The post - filter 100 is installed at the air outlet of the adsorption twin - tower dryer 200;

[0036] The adsorption type twin-tower dryer 200 is installed vertically and includes an air inlet end cover 201, an aluminum alloy cylinder body 210, an air outlet end cover 207, and a check valve assembly 208. The air inlet end cover 201 is locked on the bracket 500. There are two aluminum alloy cylinder bodies 210, which are respectively fastened between the air inlet end cover 201 and the air outlet end cover 207. Inside each aluminum alloy cylinder body 210, there are a first diffusion structure 202, a first support frame 203, an adsorption material encapsulation cylinder 204, a protection device 205, a second support frame 206, and a second diffusion structure 211. The first diffusion structure 202 and the first support frame 203 are installed on the air inlet end cover 201. The adsorption material encapsulation cylinder 204 is installed on the first support frame 203. The protection device 205 is installed on the adsorption material encapsulation cylinder 204. The second support frame 206 is installed between the protection device 205 and the air outlet end cover 207. The second diffusion structure 211 is installed on the air outlet end cover 207, forming an adsorption tower body or a backflush regeneration tower body. There are two check valve assemblies 208, which are respectively installed inside the air outlet end cover 207. Each tower body is controlled by an independent check valve assembly 208. A flow channel for backflush regeneration gas is provided at the central position of the check valve assembly 208;

[0037] An air inlet channel 201-2, an exhaust channel 201-3, and an air outlet channel 201-4 are provided inside the air inlet end cover 201. Two control solenoid valves 201-1 are provided on the outer side of the air inlet end cover 201, one corresponding to each tower body. All the control solenoid valves 201-1 are connected to the control box 300 and work state switching is controlled according to the preset program of the control box 300.

[0038] In this embodiment, the adsorption material encapsulation cylinder 204 is composed of a packaging end cover, an aluminum alloy cylinder body, and sheet-shaped adsorption materials. The sheet-shaped adsorption materials are made of aluminosilicate and have an open porous structure with a high adsorption density. The sheet-shaped adsorption materials do not generate dust particles during use. At the same time, since the sheet-shaped adsorption materials do not contain clay components, they have the characteristic of being water-saturated resistant (will not degrade when soaked in water); the sheet-shaped adsorption materials are in a long strip multi-layer winding structure inside the aluminum alloy cylinder body. The gap between each layer is a gas flow channel. When compressed air passes through the gap, no friction occurs between the sheet-shaped adsorption materials, enabling them to have excellent mechanical properties and regeneration performance without generating dust. This design can control the speed, contact time, turbulence, back pressure, and adsorption density by adjusting the layer gap, with the aim of maximizing the adsorption capacity. The layer gap is preferably 1 mm; Polymer gaskets for filtration treatment can be provided at both ends inside the aluminum alloy cylinder body. The adsorption material encapsulation cylinder has the advantages of extremely simple installation and replacement, reducing the production and maintenance time of the dryer.

[0039] In this embodiment, the aluminum alloy cylinder body 210 is connected to the intake end cover 201 and the outlet end cover 207 through bolts via the threaded holes on both sides, and an O-ring 209 is arranged between the aluminum alloy cylinder body 210 and the intake end cover 201 and the outlet end cover 207 for sealing.

[0040] In this embodiment, one side of the first diffusion structure 202 is a precision machined concave surface body. Four counterbores are arranged at the outer circumference of the first diffusion structure for installing the heads of the four bolts locking the first diffusion structure into the first diffusion structure to prevent the protruding fastening bolt heads from interfering with the flow of compressed air in the cylinder body. The second diffusion structure 211 is the same as the first diffusion structure 202.

[0041] In this embodiment, both the first support frame 203 and the second support frame 206 are cylindrical structures.

[0042] In this embodiment, the protection device 205 is a spoke-shaped flat plate. Four spokes are arranged between the solid hub and the rim. The solid hub presses on the center of the adsorption material encapsulation cylinder, and the rim is located between the adsorption material encapsulation cylinder and the second support frame.

[0043] In this embodiment, the one-way valve assembly 208 includes a one-way valve cover plate 208-1, a guide sleeve 208-2, a one-way valve cover plate sealing ring 208-3, a one-way valve spring 208-4, and a one-way valve plate 208-5. The guide sleeve 208-2 is installed on the one-way valve cover plate 208-1. The one-way valve spring 208-4 is sleeved on the outer side of the upper part of the one-way valve plate 208-5, and the upper end of the one-way valve plate 208-5 extends into the guide sleeve 208-2. The one-way valve cover plate 208-1 is installed on the outlet end cover 207. The one-way valve cover plate sealing ring 208-3 is installed between the one-way valve cover plate 208-1 and the outlet end cover 207. The lower end surface of the one-way valve plate 208-5 is provided with vulcanized rubber, and a communication hole 208-6 is arranged at the central position of the one-way valve plate 208-5 as the flow channel for the backflush regeneration gas. Therefore, it is not necessary to arrange a separate regeneration gas flow channel and a flow control device on the outlet end cover 207, simplifying the flow channel design of the end cover and reducing components to improve the reliability of the dryer.

[0044] In this embodiment, the control solenoid valve 201-1 is a normally open function solenoid valve with two positions and three passages and spring return, which can ensure that even in the case of a solenoid valve coil or control system failure, compressed air can still pass through the solenoid valve from the intake passage 201-2 in and out of the dryer tower body and provide compressed air for downstream equipment. The exhaust passage 201-3 of the backflush regeneration gas adopts a large-diameter design to reduce the pressure in the regeneration tower body during the backflush regeneration of the dryer, improve the regeneration efficiency, reduce the consumption of the backflush regeneration gas, and at the same time, a muffler 201-5 is installed at the outlet of the exhaust passage 201-3 to reduce the noise during the operation of the device.

[0045] A method for cleaning and drying compressed air implemented by using the said device is as follows:

[0046] The compressed air generated by a compressor enters the pre-filter 400 through the air inlet a for pretreatment, separating and filtering out impurities such as liquid water, lubricating oil, particles, and aerosol / hydroaerosol contained in the compressed air. A drain solenoid valve is installed at the bottom of the pre-filter 400, which is opened according to the time sequence set in the control box 300 to discharge the separated pollutants. The compressed air treated by the pre-filter 400 enters the adsorption twin-tower dryer 200, and the adsorption twin-tower dryer 200 removes the gaseous water contained in the compressed air, and discharges it from the air outlet b to provide dry compressed air for downstream equipment, and switches the states of the twin towers according to the time sequence set in the control box 300. A post-filter 100 is provided at the air outlet to play a role of redundancy and protection.

[0047] Specifically, by controlling the control solenoid valve 201-1 of the adsorption tower body and the back-blow regeneration tower body through the control box 300, the state of the dryer tower body is determined. That is, for the tower body in the adsorption state, its air inlet channel 201-2 is communicated with the air outlet channel 201-4, so that the compressed air enters the tower body for adsorption drying, while the exhaust channel 201-3 is not communicated with the air outlet channel 201-4, and the compressed air can only flow towards the air outlet end cover 207; at the same time, for the tower body in the back-blow regeneration state, its air inlet channel 201-2 is not communicated with the air outlet channel 201-4, so that the compressed air cannot enter the tower body, while the exhaust channel 201-3 is communicated with the air outlet channel 201-4, so that the back-blow regeneration gas can flow out of the tower body and enter the muffler 201-5 installed at the outlet of the exhaust channel 201-3, and then be discharged to the atmosphere from the muffler 201-5;

[0048] Inside the adsorption tower body, the air inlet on the air inlet end cover 201 and the air outlet on the air outlet end cover 207 are both located at the center of the end cover boss, that is, at the center of the aluminum alloy cylinder body 210. High-pressure and high-speed compressed air flows out from the air inlet of the air inlet end cover 201. Under the action of the first diffusion structure 202 installed on the inner side of the air inlet end cover 201, it evenly blows towards the surroundings of the aluminum alloy cylinder body 210. At the same time, the first support frame 203 arranged between the inner side of the air inlet end cover 201 and the adsorption material encapsulation cylinder 204 constructs a sufficient space to further reduce the flow rate of the compressed air, ensuring that the compressed air evenly and slowly passes through the adsorption material encapsulation cylinder 204, and ensuring that the adsorption material fully adsorbs the moisture in the compressed air. A protection device 205 is arranged at the rear end of the adsorption material encapsulation cylinder 204 and is fixed above the adsorption material encapsulation cylinder 204 by the second support frame 206 above the protection device 205. The protection device 205 fits with the boss at the center of the adsorption material encapsulation cylinder 204 to enhance the support strength of the adsorption material encapsulation cylinder 204 and ensure the stable and safe operation of the adsorption material encapsulation cylinder 204 under high pressure. The compressed air after drying treatment passes through the one-way valve assembly 208 and then is discharged from the flow channel in the air outlet end cover 207 from the adsorption twin-tower dryer 200.

[0049] Inside the backflush regeneration tower body, the regeneration gas flowing out from the adsorption tower body blows out at high speed from the small hole in the center of the one-way valve assembly 208. Under the action of the second diffusion structure 211 on the inner side of the air outlet end cover 207, the regeneration gas evenly blows towards the surroundings of the aluminum alloy cylinder body 210. At the same time, the second support frame 206 arranged between the inner side of the air outlet end cover 207 and the adsorption material encapsulation cylinder 204 constructs a sufficient space to further reduce the flow rate and pressure of the regeneration gas. Since the backflush regeneration gas channel of the air inlet end cover 201 adopts a large-diameter design, the pressure inside the backflush regeneration tower body is further reduced, ensuring that the regeneration gas completely purges the water vapor precipitated in the adsorption material, improving the regeneration efficiency and reducing the consumption of the backflush regeneration gas.

[0050] When the state of the double towers is about to switch, under the control of the preset program in the control box, the control solenoid valve of the tower body in the backflush regeneration state acts, so that its air inlet channel 201-2 and the air outlet channel 201-4 become connected, and compressed air can enter the tower body, while the exhaust channel 201-3 and the air outlet channel 201-4 become disconnected, and the compressed air can only flow towards the air outlet end cover 207. At this time, the adsorption material encapsulation cylinder 204 in the tower body begins to adsorb the moisture in the compressed air, that is, it has been converted into an adsorption tower, and the pressure in the tower body rises rapidly in a short time. When the check valve plate 208-5 in the one-way valve assembly 208 of the original backflush regeneration tower body is completely opened, the pressure in the original backflush regeneration tower body is the same as the pressure in the adsorption tower body. This process is called the pressure holding stage of the backflush regeneration tower; under the control of the preset program in the control box, the control solenoid valve of the tower body in the adsorption state acts, its air inlet channel 201-2 and the air outlet channel 201-4 become disconnected, so that compressed air can no longer enter the tower body, while the exhaust channel 201-3 and the air outlet channel 201-4 become connected, so that the gas in the adsorption tower body quickly flows out of the tower body and enters the muffler 201-5 installed at the outlet of the exhaust channel 201-3, and then is discharged to the atmosphere from the muffler 201-5. During this process, the pressure inside the adsorption tower body drops rapidly, resulting in the rapid closing of the check valve plate 208-5 in its one-way valve assembly 208, and the backflush regeneration gas reversely enters the tower body through the communication hole 208-6, making its state converted into the backflush regeneration state; thus, the state of the double towers has switched. Under the control of the preset program in the control box, the states of the double towers are cyclically switched, so that the adsorption type double tower dryer 200 can work continuously.

Claims

1. A device for cleaning and drying compressed air, comprising a bracket, a pre-filter, a control box and an adsorption twin-tower dryer, characterized in that: The pre-filter and the control box are installed on the front side of the bracket, and the adsorption twin-tower dryer is installed on the rear side of the bracket. The pre-filter and the adsorption twin-tower dryer are connected by a pipeline. The adsorption twin-tower dryer includes an air inlet end cover, an aluminum alloy cylinder body, an air outlet end cover and a check valve assembly. The air inlet end cover is installed on the bracket. There are two aluminum alloy cylinder bodies, which are respectively installed between the air inlet end cover and the air outlet end cover. Inside each aluminum alloy cylinder body, there are a first diffusion structure, a first support frame, an adsorption material encapsulation cylinder, a protection device, a second support frame and a second diffusion structure. The adsorption material encapsulation cylinder consists of an encapsulation end cover, an aluminum alloy cylinder body and sheet-shaped adsorption materials. The sheet-shaped adsorption materials are in a long-strip multi-layer winding structure inside the aluminum alloy cylinder body, and the gap between each layer is a gas flow channel. The first diffusion structure and the first support frame are installed on the air inlet end cover. The adsorption material encapsulation cylinder is installed on the first support frame. The protection device is installed on the adsorption material encapsulation cylinder. The second support frame is installed between the protection device and the air outlet end cover. The second diffusion structure is installed on the air outlet end cover to form an adsorption tower body or a backflush regeneration tower body. There are two check valve assemblies, which are respectively installed inside the air outlet end cover. Each tower body is controlled by an independent check valve assembly. The check valve assembly is provided with a flow channel for backflush regeneration gas. The air inlet end cover is provided with an air inlet channel, an exhaust channel and an air outlet channel. On the outer side of the air inlet end cover, there are two control solenoid valves, one corresponding to each tower body. All the control solenoid valves are connected to the control box to switch the working state. One side of the first diffusion structure is a precision machined concave surface body. Four counterbores are arranged at the outer circumference of the first diffusion structure for installing the heads of four bolts for locking the first diffusion structure into the first diffusion structure. The second diffusion structure is the same as the first diffusion structure. The check valve assembly includes a check valve cover plate, a guide sleeve, a check valve cover plate sealing ring, a check valve spring and a check valve plate. The guide sleeve is installed on the check valve cover plate. The check valve spring is sleeved on the outer side of the upper part of the check valve plate, and the upper end of the check valve plate extends into the guide sleeve. The check valve cover plate is installed on the air outlet end cover. The check valve cover plate sealing ring is installed between the check valve cover plate and the air outlet end cover. The lower end surface of the check valve plate is provided with vulcanized rubber. The check valve plate is provided with a communication hole as a flow channel for backflush regeneration gas.

2. The device for cleaning and drying compressed air according to claim 1, characterized in that: The aluminum alloy cylinder body is connected to the air inlet end cover and the air outlet end cover by bolts through the threaded holes on both sides, and an O-ring is arranged between the aluminum alloy cylinder body and the air inlet end cover and the air outlet end cover for sealing.

3. The device for cleaning and drying compressed air according to claim 1 or 2, characterized in that: Both the first support frame and the second support frame are cylindrical structures.

4. The device for cleaning and drying compressed air according to claim 1 or 2, characterized in that: The protection device is a spoke-shaped flat plate. Four spokes are arranged between the solid hub and the rim. The solid hub presses the center of the adsorption material encapsulation cylinder, and the rim is located between the adsorption material encapsulation cylinder and the second support frame.

5. The device for cleaning and drying compressed air according to claim 1 or 2, characterized in that: The control solenoid valve is a normally open function solenoid valve with two positions and three passages and spring return.

6. The device for cleaning and drying compressed air according to claim 1 or 2, characterized in that: A muffler is installed at the outlet of the exhaust channel.

7. The device for cleaning and drying compressed air according to claim 1 or 2, characterized in that: A post-filter is also provided, and the post-filter is installed at the air outlet of the adsorption twin-tower dryer.

8. A method for cleaning and drying compressed air implemented by the device according to claim 1, characterized in that: The compressed air generated by the compressor enters the pre-filter through the air inlet for pretreatment. The compressed air treated by the pre-filter enters the adsorption twin-tower dryer, and the gaseous water contained in the compressed air is removed by the adsorption twin-tower dryer. It is discharged from the air outlet to provide dry compressed air for downstream equipment, and the state of the twin towers is switched according to the timing set in the control box; Specifically, the control solenoid valves of the adsorption tower body and the backflush regeneration tower body are controlled by the control box to determine the state of the dryer tower body. That is, for the tower body in the adsorption state, its air inlet channel is connected to the air outlet channel, so that the compressed air enters the tower body for adsorption drying, while the exhaust channel is not connected to the air outlet channel, and the compressed air can only flow towards the air outlet end cover side; at the same time, for the tower body in the backflush regeneration state, its air inlet channel is not connected to the air outlet channel, so that the compressed air cannot enter the tower body, while the exhaust channel is connected to the air outlet channel, so that the backflush regeneration gas flows out of the tower body and enters the exhaust channel and is discharged to the atmosphere; Inside the adsorption tower body, the compressed air flows out from the air inlet of the air inlet end cover. Under the action of the first diffusion structure installed on the inner side of the air inlet end cover, it is evenly blown to the surroundings of the aluminum alloy cylinder body. At the same time, the first support frame arranged between the inner side of the air inlet end cover and the adsorption material encapsulation cylinder constructs a sufficient space to further reduce the flow rate of the compressed air, ensuring that the compressed air evenly and slowly passes through the adsorption material encapsulation cylinder, ensuring that the adsorption material fully adsorbs the moisture in the compressed air. A protection device is arranged at the rear end of the adsorption material encapsulation cylinder and is fixed above the adsorption material encapsulation cylinder by the second support frame above the protection device. The protection device fits with the boss at the center of the adsorption material encapsulation cylinder to enhance the support strength of the adsorption material encapsulation cylinder and ensure the stable and safe operation of the adsorption material encapsulation cylinder under high pressure; the compressed air after drying treatment passes through the one-way valve assembly and is discharged from the flow channel in the air outlet end cover from the adsorption twin-tower dryer; Inside the backflush regeneration tower body, the regeneration gas flowing out from the adsorption tower body blows out from the hole in the center of the one-way valve assembly. Under the action of the second diffusion structure on the inner side of the air outlet end cover, the regeneration gas is evenly blown to the surroundings of the aluminum alloy cylinder body. At the same time, the second support frame arranged between the inner side of the air outlet end cover and the adsorption material encapsulation cylinder constructs a sufficient space to further reduce the flow rate and pressure of the regeneration gas, ensuring that the regeneration gas completely purges the water vapor precipitated in the adsorption material, improving the regeneration efficiency and reducing the consumption of the backflush regeneration gas; When the state of the double towers is about to switch, under the control of the preset program in the control box, the control solenoid valve of the tower body in the backflush regeneration state acts, making its air inlet channel communicate with the air outlet channel, so that compressed air enters the tower body, while the exhaust channel and the air outlet channel become non - communicating, and the compressed air can only flow towards the air outlet end cover side. At this time, the adsorption material encapsulation cylinder in the tower body starts to adsorb the moisture in the compressed air, that is, it has been converted into an adsorption tower, and the pressure in the tower body rises rapidly in a short time. When the check valve plate in the one - way valve assembly of the original backflush regeneration tower body is fully opened, the pressure in the original backflush regeneration tower body is the same as that in the adsorption tower body. This process is called the pressure - maintaining stage of the backflush regeneration tower; under the control of the preset program in the control box, the control solenoid valve of the tower body in the adsorption state acts, its air inlet channel and the air outlet channel become non - communicating, so that compressed air can no longer enter the tower body, while the exhaust channel and the air outlet channel become communicating, so that the gas in the adsorption tower body quickly flows out of the tower body and enters the exhaust channel and is discharged to the atmosphere. During this process, the pressure inside the adsorption tower body drops rapidly, resulting in the rapid closing of the check valve plate in its one - way valve assembly, and the backflush regeneration gas reversely enters the tower body from the communication hole, making its state convert to the backflush regeneration state; thus, the state of the double towers has switched. Under the control of the preset program in the control box, the states of the double towers are cyclically switched, enabling the adsorption - type double - tower dryer to work continuously.

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